Apoprotein Intermolecular Interactions and Heme Insertion for 3D Domain Swapping in Myoglobin

ACS Omega, Год журнала: 2025, Номер 10(7), С. 7039 - 7047

Опубликована: Фев. 11, 2025

Many proteins, including heme proteins undergo three-dimensional domain swapping (3D-DS). The loop between E and F helices is converted to a helical structure in the myoglobin (Mb) 3D-DS dimer. However, relationship insertion Mb remains unclear. Here, we systematically investigated propensity of wild-type (WT) its variant which one three Ala residues were introduced into hinge region: G80A (K3AH2), G80A/H81A (K3A2H), G80A/H81A/H82A (K3A3). After heating monomer at 70 °C for 30 min, no dimers detected WT Mb, whereas formed by 55 ± 1%, 92 2%, 84 2% protein molecules K3AH2, K3A2H, K3A3 variants, respectively, with K3A2H dimer being stabilized hydrogen bond network region. When expressed purified from Escherichia coli, ratio increased order (1 1%) < K3AH2 (16 3%) (35 (82 5%). A similar was observed obtained upon reconstitution apo Mb. exhibited higher propensities than forms other variants. Molecular dynamics studies supported hypothesis that stabilization α-helices region enhances formation compared These results indicate vivo depends on monomer–dimer equilibrium before insertion, showing significantly influenced protein-folding conditions.

Язык: Английский

Rational Design of an Artificial Metalloenzyme by Constructing a Metal-Binding Site Close to the Heme Cofactor in Myoglobin

Inorganic Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Сен. 23, 2024

In this study, we constructed a metal-binding site close to the heme cofactor in myoglobin (Mb) by covalently attaching nonnative ligand of bipyridine Cys46 through F46C mutation distal site. The X-ray structure designed enzyme, termed F46C-mBpy Mb, was solved Cu(II)-bound form, which revealed formation heterodinuclear center Cu-His-H

Язык: Английский